This past weekend I traveled to southeastern Minnesota to visit family and camp at Forestville State Park near Preston in Fillmore County. Forestville State Park resides in the Root River Valley, a unique area in the southeast corner of the state. Newton Horace Winchell, State Geologist and director of the Minnesota Geological and Natural History Survey, first recorded the geology of Fillmore County in his fourth annual report. Although his account was written in the late 1870s, his observations still apply today. Here are a few sections:
“Fillmore county lies adjacent to the State of Iowa, and is separated from the Mississippi River by Houston county. It lies next east of Mower county… It contains no lakes, and but few acres that are unsuited to farm tillage. Preston is the county seat. Lanesboro, Spring Valley, Chatfield and Rushford are the principal towns.
Root river, with its tributaries, drains nearly the whole of the county… flowing toward the east, spreads out its tributaries north and south, like the rays of a fan, crossing the entire country from west to east. Many of the branches of the Root river rise in the counties next west and north of Fillmore county, in a tract of country covered with northern drift. After entering Fillmore county, they soon enter canon-like valleys, and the drift becomes much lighter. They then converge toward the main valley, following deeply cut rocky valleys, and leave the county in one volume at Rushford, in the northeastern corner of the county…
… The valley of this stream, with its principal tributaries, presents some of the most remarkable and instructive phenomena of erosion to be found in the state.
While the immediate valleys of Root river and its tributaries are apt to be rocky, the country that spread out in either direction, after leaving the valleys, is not rough.”
If Winchell’s words do not allow you to form a complete image of the valleys of the region for you, I have a few visual aids to supplement his description. Just this morning, I opened Box 30 of the botanical images in the Department of Botany collection and found a series of photographs taken in Fillmore County in 1902. The following are three images of the valley of the South fork of the Root River, Fillmore County, taken in June of 1902:
To my delight, these images reminded me of the peaceful and scenic car ride through Fillmore County to and from the campground at Forestville, and made me forget all about the pouring rain that clamored against my tent all night long.
(For a more detailed description of the geological structure of Fillmore County, read the full report on the Digital Conservancy in The Geological and Natural History Survey of Minnesota. The fourth annual report for the year 1875.)